A disc stepping motor

Abstract

The invention discloses a disc stepping motor, wherein the rotor assembly comprises two rotor cores clamping an annular magnet, 2n rotor convex teeth are evenly distributed along the circumference of the rotor core, the center angle between the centers of adjacent rotor convex teeth is degrees, the stator assembly comprises four fan-shaped stator cores, and a coil package arranged on the back of the stator core, n stator convex teeth corresponding to the rotor convex teeth are arranged at equal intervals on the outer circumference of each stator core, and the center angle between the centers of adjacent stator convex teeth is degrees; every two stator cores are arranged opposite to a rotor core, and the center angles between two adjacent groups of stator convex teeth of the two stator cores on the same side are degrees and degrees respectively; wherein n is a positive integer greater than 1. It has the characteristics of simple structure, low requirements on processing accuracy, and can compress the axial dimension to be very flat.

Description

Technical Field

[0001] The present invention relates to the technical field of stepping motors, and more specifically, to a disc-type stepping motor. Background Art

[0002] A stepper motor is a motor that converts electrical pulse signals into corresponding angular displacement or linear displacement. Each time a pulse signal is input, the rotor rotates an angle or moves forward one step. The angular displacement or linear displacement output is proportional to the number of input pulses, and the speed is proportional to the pulse frequency. Therefore, a stepper motor is also called a pulse motor.

[0003] The existing disc stepper motor has a single-side magnetic pole of the rotor with both an N pole and an S pole. The magnetic steel needs to be magnetized with multiple poles. High-precision processing is required at all parts of the rotor and the stator to achieve very high-precision coaxiality between the stator and the rotor. The processing technology is demanding, and since many magnetic poles need to be pasted on the side of the rotor, the disc stepper motor is larger in size.

[0004] Therefore, how to solve the problem that the existing disc stepper motor is difficult to process and has a large size is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a disc stepping motor, which can ensure high-precision coaxiality between the stator and the rotor without high-precision processing in various places, and the axial dimension is also compressed to a very flat size to reduce the overall size of the motor.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A disc-type stepping motor comprises a rotor assembly and a stator assembly which are arranged opposite to each other;

[0008] The rotor assembly includes an annular magnet and two rotor cores clamping the annular magnet. On the outer circumference of the outer end surface of the rotor core, 2n rotor convex teeth are evenly distributed along the circumference, and the center angle between the centers of adjacent rotor convex teeth is degrees, and the tooth slots on the two rotor cores are opposite to each other;

[0009] The stator assembly comprises four fan-shaped stator cores symmetrically arranged on both sides of the rotor assembly, and a coil package arranged on the back of the stator core. On the outer circumference of each stator core, n stator convex teeth corresponding to the rotor convex teeth are arranged at equal intervals, and the central angle between the centers of adjacent stator convex teeth is Spend;

[0010] Every two stator cores are arranged opposite to one rotor core, and the center angles between two adjacent groups of stator teeth of the two stator cores on the same side are respectively Spend, Spend;

[0011] Wherein, n is a positive integer greater than 1.

[0012] Preferably, it includes a rotating shaft, the annular magnet is sleeved on the rotating shaft, the two rotor cores are sleeved on the rotating shaft and clamp the annular magnet back to back, the rotating shaft is also sleeved with a shaft sleeve and a bearing on the outer side of the rotor core, the front end cover and the rear end cover are fixed on the bearing, and the stator core is fixed in the front end cover and the rear end cover.

[0013] Preferably, the annular magnet is annular magnetic steel.

[0014] Preferably, a first annular step is provided on the outer wall of the front end cover, and a second annular step is provided on the inner wall of the rear end cover, and the first annular step and the second annular step are interference fit.

[0015] Preferably, the coil package is adhered to the back of the stator core.

[0016] Preferably, the gap between the rotor core and the stator core is 0.1-0.2 mm.

[0017] Preferably, the rotor core is provided with 12 rotor teeth.

[0018] Preferably, the rotor teeth and the stator teeth are triangular teeth of the same size.

[0019] Preferably, the rotor teeth and the stator teeth are trapezoidal teeth of the same size.

[0020] Preferably, the maximum width of the rotor teeth is equal to the distance between adjacent rotor teeth, the maximum width of the stator teeth is equal to the distance between adjacent stator teeth, and the stator teeth are the same size as the rotor teeth.

[0021] The disc stepping motor provided by the present invention has rotor convex teeth arranged on the rotor core and stator convex teeth arranged on the stator core, and the stator convex teeth on the stator core are staggered with the rotor convex teeth on the rotor core by a certain angle. By sequentially controlling the power-on sequence of the coil packages on the four stator cores and utilizing the attraction between the rotor convex teeth and the stator convex teeth, the rotor assembly can be driven to rotate in steps. The disc stepping motor has the characteristics of simple structure and low requirements on processing accuracy.

[0022] Compared with the existing common stepper motor with radial magnetic flux structure of inner rotor and outer stator, the present invention does not need high-precision processing everywhere, and can achieve high-precision coaxiality between the stator assembly and the rotor assembly. In addition, since the single-side magnetic pole of the existing disc stepper motor rotor has both N pole and S pole, the magnetic steel needs multi-pole magnetization, resulting in a large axial size. The present invention only needs unidirectional magnetization, and the magnetization process is simple and convenient. The axial size of the disc stepper motor can be compressed to a very flat size to increase its application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 A schematic diagram of a specific embodiment of a disc-type stepping motor provided by the present invention;

[0025] Figure 2 is a schematic diagram of the rotor core;

[0026] Figure 3 It is a front view schematic diagram of two stator cores located on the same side;

[0027] Figure 4 It is a schematic diagram of the back of two stator cores located on the same side;

[0028] Figure 5 It is a schematic diagram of the stepping principle of the disc stepping motor provided by the present invention.

[0029] Among them, 1-rotating shaft, 2-bearing, 3-sleeve, 4-stator core, 41-stator convex teeth, 401-first group of stator cores, 402-second group of electronic cores, 403-third group of stator cores, 404-fourth group of stator cores, 5-coil package, 6-front end cover, 7-rotor core, 71-rotor convex teeth, 8-annular magnetic steel, 9-rear end cover. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The core of the present invention is to provide a disc-type stepping motor, which can ensure high-precision coaxiality between the stator and the rotor without high-precision processing at various locations, and the axial dimension is also compressed to be very flat to reduce the overall size of the motor.

[0032] Please refer to Figures 1 to 5 , Figure 1 A schematic diagram of a specific embodiment of a disc-type stepping motor provided by the present invention; Figure 2 is a schematic diagram of the rotor core; Figure 3 It is a front view schematic diagram of two stator cores located on the same side; Figure 4 It is a schematic diagram of the back of two stator cores located on the same side; Figure 5 It is a schematic diagram of the stepping principle of the disc stepping motor provided by the present invention.

[0033] The disc-type stepping motor provided by the present invention comprises a rotor assembly and a stator assembly which are arranged opposite to each other;

[0034] The rotor assembly includes an annular magnet and two rotor cores 7 holding the annular magnet. On the outer periphery of the outer end surface of the rotor core 7, 2n rotor convex teeth 71 are evenly distributed along the circumference, and the center angle between the centers of adjacent rotor convex teeth 71 is Spend;

[0035] The stator assembly includes four fan-shaped stator cores 4 symmetrically arranged on both sides of the rotor assembly, and a coil package 5 arranged on the back of the stator core 4. On the outer periphery of each stator core 4, n stator convex teeth 41 corresponding to the rotor convex teeth 71 are arranged at equal intervals, and the center angle between the centers of adjacent stator convex teeth 41 is Spend;

[0036] Every two stator cores 4 are arranged opposite to one rotor core 7, and the center angles between two adjacent groups of stator teeth 41 of the two stator cores 4 on the same side are respectively Spend;

[0037] Wherein, n is a positive integer greater than 1.

[0038] The stator assembly and the rotor assembly are arranged opposite to each other, so that the magnetic poles generated by the stator assembly drive the rotor assembly to rotate, wherein the rotor assembly includes an annular magnet and two rotor cores 7 clamping the annular magnet, so that the magnetic force of the annular magnet acts on the rotor core 7, so that the rotor core 7 is magnetized, and the outer end face of one rotor core is an S pole, and the outer end face of the other rotor core 7 is an N pole. It should be noted that the outer end face here refers to the end face of the rotating core away from the annular magnet, that is, the end face facing the stator assembly.

[0039] The outer circumference of the outer end surface of the rotor core 7 is also provided with rotor convex teeth 71, and the rotor convex teeth 71 are evenly distributed on the outer end surface of the rotor core 7 along the circumference, so that a strictly staggered tooth and slot structure is formed on the outer end surface of the rotor core 7. According to the gravitational formula, the gravitational force is negatively correlated with the distance, and the smaller the distance, the greater the gravitational force. Therefore, the distance between the rotor convex teeth 71 and the stator assembly is closer, so the gravitational force of the stator assembly on the rotor core 7 mainly acts through the gravitational force on the rotor convex teeth 71.

[0040] The tooth grooves on the two rotor cores 7 are opposite to each other, that is, the rotor protruding teeth 71 on one rotor core 7 are directly opposite to the grooves between the adjacent rotor protruding teeth 71 on the other rotor core 7 .

[0041] The stator assembly includes four fan-shaped stator cores 4, and each stator core 4 is provided with a coil package 5 on the back. The coil package 5 is used for driving circuit connection, so that the driving circuit can energize each coil package 5 in a certain order, so that the stator core 4 generates magnetic poles to generate attraction for the rotor core 7.

[0042] The stator core 4 is a fan-shaped structure, and every two stator cores 4 are arranged opposite to one rotor core 7. The stator core 4 is provided with stator convex teeth 41, and the stator convex teeth 41 correspond to the rotor convex teeth 71 at equal intervals. In this way, when the coil package 5 on the back of the stator core 4 is energized, the stator core 4 generates magnetic poles that attract each other with the rotor core 7, and because the distance between the stator convex teeth 41 and the rotor convex teeth 71 is the shortest, the attraction between the stator core 4 and the rotor core 7 is mainly through the mutual attraction between the stator convex teeth 41 and the rotor convex teeth 71.

[0043] The stepping principle of the disc stepping motor provided by the present invention is described in detail below. Figure 5 As shown, for the convenience of description, the rotor core 7 is provided with 12 rotor protruding teeth 71 as an example for description:

[0044] Since the rotor core 7 is provided with 12 rotor teeth 71, n=6, that is, each sector-shaped stator core 4 has 6 stator teeth 41, and the center angle between the centers of adjacent rotor teeth 71 is 30 degrees, and the center angle between the centers of adjacent stator teeth 41 is 28.75 degrees; the two sides of the rotor are different magnetic poles, and the tooth slots of the two rotor cores 7 are opposite, and there are four stator cores 4 in total, and each stator core 4 is energized separately to generate magnetic poles.

[0045] At the initial moment, Figure 5In the first row, the coil package 5 on the first group of stator cores 401 is energized, and the first group of stator cores 401 generates an S pole, which attracts the N pole rotor core 7. Since the attraction between the stator core 4 and the rotor core 7 is mainly through the mutual attraction between the stator teeth 41 and the rotor teeth 71, the six stator teeth 41 on the stator core 4 will respectively generate the maximum attraction on the nearest rotor teeth 71 on the rotor core 7, that is, they will respectively attract rotor teeth No. 1-6 on the rotor core 7, and finally make the magnetic pole center lines of rotor teeth No. 1-6 on the rotor core 7 coincide with the magnetic pole center lines of the six stator teeth 41 on the first group of stator cores 401.

[0046] That is, the magnetic center line of the first group of stator cores 401 is between stator teeth 41 No. 3 and No. 4, so that the rotor core 7 rotates according to the center line position formed by the magnetic force of the stator core 4, and finally the center line of rotor teeth 71 No. 1-6 on the rotor core 7 coincides with the center line of the first group of stator teeth 41, so as to achieve a position where the magnetic fields of the stator core 4 and the rotor core 7 are aligned and the magnetic force is stable.

[0047] Then the second set of stator cores 402 are energized to generate S poles, such as Figure 5 In the second row, since the central angles between the two adjacent groups of stator teeth 41 of the two stator cores 4 located on the same side are A = 28.75 degrees and B = 43.75 degrees respectively, the central angle of the magnetic pole centerline between the second group of stator cores 402 and the first group of stator cores 401 is 172.5 degrees, and the central angle of the magnetic pole centerline between the rotor cores 7 No. 1-6 and the rotor cores 7 No. 7-12 is 180 degrees.

[0048] Therefore, when the coil package 5 on the second group of stator cores 402 is energized, an attractive force is generated between the six stator teeth 41 on the second group of stator cores 402 and the rotor teeth 71 No. 7-12, causing the rotor in the previous position to rotate 7.5 degrees to the left, i.e., one-quarter of a tooth pitch, thereby once again reaching a position where the magnetic fields of the stator core 4 and the rotor core 7 are aligned and the magnetic force is stable.

[0049] like Figure 5 In the third row, the coil package 5 on the third group of stator cores 403 is energized, so that the third group of stator cores 403 produces an N pole. Similarly, the rotor is rotated to the left by 7.5 degrees, i.e., one-quarter of the tooth pitch, to reach a position where the magnetic field is aligned and the magnetic force is stable.

[0050] like Figure 5 In the fourth row, the coil package 5 on the fourth stator core 404 is energized, so that the fourth stator core 404 generates an N pole. Similarly, the rotor rotates 7.5 degrees to the left, that is, one quarter of the tooth pitch, to reach a stable magnetic field position.

[0051] As shown in the fifth row in the figure, the first group of stators are energized to generate S poles, and the rotor moves to the left by a quarter of a tooth pitch to reach the magnetically stable position, which is the rotor position in the first row in the figure.

[0052] By energizing the coil packages 5 on the back of the four groups of stator cores 4 in a cycle according to this rule, the rotor assembly can be stepped continuously. The rotor assembly makes a full rotation and moves a total of 48 steps, with each step being 7.5°.

[0053] The disc stepping motor provided by the present invention provides rotor convex teeth 71 on the rotor core 7 and stator convex teeth 41 on the stator core 4, and stator convex teeth 41 on the stator core 4 are staggered at a certain angle from rotor convex teeth 71 on the rotor core 7. By sequentially controlling the power-on sequence of the coil packages 5 on the four stator cores 4 and utilizing the attraction between the rotor convex teeth 71 and the stator convex teeth 41, the rotor assembly can be driven to rotate in steps. The disc stepping motor has the characteristics of simple structure and low requirements on processing accuracy.

[0054] Compared with the existing common stepper motor with radial magnetic flux structure of inner rotor and outer stator, the present invention does not need high-precision processing everywhere, and can achieve high-precision coaxiality between the stator assembly and the rotor assembly. In addition, since the single-side magnetic pole of the existing disc stepper motor rotor has both N pole and S pole, the magnetic steel needs multi-pole magnetization, resulting in a large axial size. The present invention only needs unidirectional magnetization, and the magnetization process is simple and convenient. The axial size of the disc stepper motor can be compressed to a very flat size to increase its application range.

[0055] Based on the above embodiments, Figure 1 As shown, as a preferred embodiment, it includes a rotating shaft 1, an annular magnet is sleeved on the rotating shaft 1, two rotor cores 7 are sleeved on the rotating shaft 1 and clamp the annular magnet back to back, the rotating shaft 1 is also sleeved with a shaft sleeve 3 and a bearing 2 on the outer side of the rotor core 7, a front end cover 6 and a rear end cover 9 are fixed on the bearing 2, and the stator core 4 is fixed in the front end cover 6 and the rear end cover 9.

[0056] On the basis of the above embodiments, considering the specific selection of the annular magnet, as a preferred embodiment, the annular magnet is an annular magnetic steel 8. The annular magnetic steel 8 has the advantage of stable magnetic force.

[0057] On the basis of the above embodiment, considering the specific connection method between the front cover 6 and the rear cover 9, as a preferred embodiment, a first annular step is provided on the outer wall of the front cover 6, and a second annular step is provided on the inner wall of the rear cover 9, and the first annular step and the second annular step are interference fit. Of course, the front cover 6 and the rear cover 9 can also be connected and fixed by means of threads or screws.

[0058] Based on the above embodiment, considering the specific connection mode between the coil package 5 and the stator core 4, as a preferred embodiment, the coil package 5 is adhered to the back of the stator core 4. In addition, the stator core 4 can also be fixed to the front cover 6 and the rear cover 9 by adhesion.

[0059] On the basis of the above embodiment, as a preferred embodiment, the gap between the rotor core 7 and the stator core 4 is 0.1-0.2 mm. In this embodiment, considering that a certain distance should be maintained between the rotor core 7 and the stator core 4 to ensure the normal rotation of the rotor assembly, and the distance between the rotor core 7 and the stator core 4 should not be too large to ensure that there is sufficient attraction between the rotor core 7 and the stator core 4, specifically, the spacing between the rotor core 7 and the stator core 4 is 0.1-0.2 mm.

[0060] On the basis of the above embodiment, considering the specific number of the rotor teeth 71 on the rotor core 7, as a preferred embodiment, 12 rotor teeth 71 are provided on the rotor core 7. Of course, the number of the rotor teeth 71 can also be selected as other numbers as needed. Specifically, it should be flexibly set according to the angle required for each step of rotation. The disc stepper motor provided by the present invention rotates the angle of one tooth in four steps.

[0061] On the basis of the above embodiment, considering the specific shape settings of the rotor protruding teeth 71 and the stator protruding teeth 41, as a preferred embodiment, the rotor protruding teeth 71 and the stator protruding teeth 41 are triangular protruding teeth of the same size. In another embodiment of the shape of the rotor protruding teeth 71 and the stator protruding teeth 41, the rotor protruding teeth 71 and the stator protruding teeth 41 are trapezoidal protruding teeth of the same size. Among them, the trapezoidal protruding teeth can be formed by removing the sharp corners of the triangular protruding teeth in the figure, so that the teeth are formed into a trapezoid along the radial direction, and the teeth can also be formed into a trapezoid along the axial direction.

[0062] Based on any of the above embodiments, as a preference, the maximum width of the rotor teeth 71 is equal to the distance between adjacent rotor teeth 71 , the maximum width of the stator teeth 41 is equal to the distance between adjacent stator teeth 41 , and the stator teeth 41 are the same size as the rotor teeth 71 .

[0063] like Figure 5 As described above, in this embodiment, the maximum width of the rotor teeth 71 is equal to the spacing between adjacent rotor teeth 71 , and the maximum width of the stator teeth 41 is equal to the distance between adjacent stator teeth 41 , so as to ensure the accuracy of stepping.

[0064] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0065] The above is a detailed introduction to the disc stepper motor provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A disc stepping motor, characterized in that: It includes a rotor assembly and a stator assembly which are arranged opposite to each other; The rotor assembly comprises an annular magnet and two rotor cores (7) clamping the annular magnet. 2n rotor convex teeth (71) are evenly distributed along the circumference on the outer end surface of the rotor core (7). The center angle between the centers of adjacent rotor convex teeth (71) is The tooth slots on the two rotor cores (7) are opposite to each other; The stator assembly comprises four fan-shaped stator cores (4) symmetrically arranged on both sides of the rotor assembly, and a coil package (5) arranged on the back of the stator core (4), and n stator convex teeth (41) corresponding to the rotor convex teeth (71) are arranged at equal intervals on the outer circumference of each stator core (4), and the central angle between the centers of adjacent stator convex teeth (41) is Spend; Every two stator cores (4) are arranged opposite to one rotor core (7), and the center angles between two adjacent groups of stator teeth (41) of the two stator cores (4) located on the same side are respectively Spend, Spend; Wherein, n is a positive integer greater than 1.

2. The disc stepping motor according to claim 1, characterized in that: The invention comprises a rotating shaft (1), the annular magnet is sleeved on the rotating shaft (1), two rotor cores (7) are sleeved on the rotating shaft (1) and clamp the annular magnet back to back, the rotating shaft (1) is further sleeved with a shaft sleeve (3) and a bearing (2) on the outer side of the rotor core (7), a front end cover (6) and a rear end cover (9) are fixed on the bearing (2), and the stator core (4) is fixed inside the front end cover (6) and the rear end cover (9).

3. The disc stepping motor according to claim 2, characterized in that: The annular magnet is an annular magnetic steel (8).

4. The disc stepping motor according to claim 3, characterized in that: A first annular step is provided on the outer wall of the front end cover (6), and a second annular step is provided on the inner wall of the rear end cover (9), and the first annular step and the second annular step are interference-fitted.

5. The disc stepping motor according to claim 4, characterized in that: The coil package (5) is adhered to the back of the stator core (4).

6. The disc stepping motor according to claim 1, characterized in that: The gap between the rotor iron core (7) and the stator iron core (4) is 0.1-0.2 mm.

7. The disc-type stepping motor according to claim 6, characterized in that: The rotor iron core (7) is provided with 12 rotor convex teeth (71).

8. The disc stepping motor according to claim 7, characterized in that: The rotor convex teeth (71) and the stator convex teeth (41) are triangular convex teeth of the same size.

9. The disc-type stepping motor according to claim 7, characterized in that: The rotor convex teeth (71) and the stator convex teeth (41) are trapezoidal convex teeth of the same size.

10. The disc stepping motor according to any one of claims 1 to 9, characterized in that: The maximum width of the rotor teeth (71) is equal to the distance between adjacent rotor teeth (71), the maximum width of the stator teeth (41) is equal to the distance between adjacent stator teeth (41), and the stator teeth (41) and the rotor teeth (71) are of the same size.

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